The present invention relates to household appliances and, more particularly to a toaster oven appliance including low-profile heating elements, which provides more uniform heating, facilitate cleaning of the interior cavity, and increase the useable capacity of the oven.
Conventional toaster ovens typically utilize tubular heating elements mounted within the cooking chamber of the toaster oven. Typically an array of either two or four tubular heating elements are disposed on the inner top and/or bottom walls of the cooking chamber. Such heating elements may be constructed from stainless steel tubing or other suitable tubing wherein an electrical resistance heating wire is enclosed.
However, such heating elements have numerous disadvantages. The use of tubular heating elements provides non-uniform heating due to their position in relation to the foodstuffs in the cooking chamber. This results in a longer cooking cycle for bread and related food items than a conventional toaster. Tubular heating elements inherently make cleaning the oven more difficult and reduce the usable capacity of the oven being mounted in spaced-apart relation to the interior walls thereof.
Another disadvantage of conventional toaster ovens is the construction of the cooking chamber itself. A conventional toaster oven comprises three to four sheet metal panels secured by fasteners such as rivets to form the cooking chamber. Such toaster oven construction is relatively complex and substantially increases manufacturing costs.
One example of such a prior art toaster oven is disclosed in U.S. Pat. No. 5,694,831 to Haroun et al. which teaches a household appliance that permits simultaneous toasting of bread and cooking of food in separate cavities that are arranged within a housing wherein each of the housings is provided with respective heating elements. One of the heating elements utilized in the toaster cavity may be shiftable from a first position in the toaster compartment to a second position in the oven cavity (see Haroun et al. FIGS. 3-4).
Various other ovens with movable heating elements are known in the prior art. For example, U.S. Pat. No. 6,091,057 to Asami et al. discloses a broiler oven having a heating chamber 2, first and second movable heaters 61, 62 formed out of tubular heaters and rotatably supported by the inner walls of the heating chamber in such a way that their heating portions 62a, 62b and their shaft portions 61a, 62a joined together so as to be parallel to each other by their arm portions 61c, 62c are held at an equal level, a driving mechanism 12 for rotating the shaft portions, and a control circuit 10 for controlling the first and second movable heaters.
Another example of an oven with an automatically movable shelf is disclosed in U.S. Pat. No. 5,938,959 to Wang which teaches a domestic oven including a housing defining a cooking chamber, at least one stationary first heating element in the chamber, a second heating element mounted to the shelf, and a drive operatively connected to the shelf for translating the shelf, together with the second heating element, in the housing.
However, it will be appreciated that both the Asami et al. ('057) and Wang ('959) references utilize tubular heating elements (ie. CALROD type) described hereinabove, which effectively reduce the usable capacity of the cooking chamber and make cleaning the oven more difficult.
U.S. Pat. No. 6,476,360 to Huggler et al. discloses a method of manufacturing a unitary shell structure for a heating appliance (i.e. a toaster) providing a shell having first and second side panels and first and second end panels. The first end panel has an opening. A first outer heating element is inserted through the opening and attached to the first side panel during assembly. A second outer heating element is inserted through the opening and attached to the second side panel. It will be noted that the Huggler et al. patent is directed to a conventional toaster with a vertically-oriented chamber and not to a toaster oven with a horizontally-oriented chamber as in the manner of the present invention.
U.S. Pat. No. 7,012,221 to Li; U.S. Pat. No. 6,867,394 to Li; U.S. Pat. No. 6,686,569 to Li; and U.S. Pat. No. 6,509,550 to Li, which are commonly owned by this applicant, are also considered of interest with respect to heating element construction.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose the present toaster oven with adjustable low-profile heating elements, which increase the usable capacity of the cooking chamber, facilitate cleaning of the interior cooking cavity, and reduce the cooking time required for common food items.